Caterpillar Inc.

Other

Ralph A Smith, Iii

Steven Y Tian

David J Beatty

Daniel Richard Ibrahim

Gregory W Hefler

Richard H Holtman

Clifford E Cotton, Iii

Mike Youakim

Matthew Bredesen

An electrical actuator subassembly, preferably for use in a fuel injector, includes an externally threaded ferromagnetic metallic body, an internally threaded collar, an electrical actuator, an electrical connector, and a plastic cap. In one embodiment, the electrical actuator is a solenoid, while a piezoelectric actuator is used in a second embodiment. The electrical actuator directly controls a pilot valve member positioned between the metallic body and the injector body, and a needle valve which opens or closes a nozzle outlet at the bottom of the injector. The electrical actuator subassembly is attached to a fuel injector body by mating the external threads of the metallic body to the internal threads of the collar. The collar is attached to the injector body with a groove and snap ring configuration.

Electrical actuator subassembly with external threads and fuel injector using same

During assembly, shipping and handling before a mechanically-actuated fuel injector is installed into an internal combustion engine, the fuel injector tappet often accidentally disconnects from the fuel injector body. This separation of the tappet from the fuel injector body is caused by a force placed upon the tappet by a biasing means, such as a spring, that pushes the tappet away from the injector body. The fuel injector of the present application solves this problem through the interaction of a retention clip, a retention opening in the fuel injector body, and a retention slot in the fuel injector tappet. The retention clip has a body and a protrusion. The retention clip body is contained within the fuel injector body, and the protrusion extends through the retention opening and into the retention slot. After it is assembled, the fuel injector of the present application remains connected during shipping and handling and permits easy installation into an internal combustion engine.

Fuel injector tappet retention mechanism

A hydraulically actuated fuel injector comprises a valve body and a stepped valve member. The valve body has a wide bore portion and a narrow bore portion. The stepped valve member has a wide member section and a narrow member section. The wide member section is slidably disposed in the wide bore portion and defines a first diametrical clearance therebetween. The narrow member section and the wide bore portion define a damping chamber therebetween that is wider than the first diametrical clearance. The stepped valve member is slidable between a first position at which the damping chamber is substantially fluidly open to a low pressure hydraulic fluid reservoir, and a second position at which a fractional portion of the narrow member section is slidably disposed within a portion of the narrow bore portion defining a second diametrical clearance therebetween that is less wide than the damping chamber and substantially restricts fluid communication between the damping chamber and the reservoir.

Liquid control valve assembly with local damping and hydraulically

A fluid driven piston assembly, preferably for use in a hydraulically-actuated fuel injector, includes a body that defines an actuation fluid cavity and a piston bore. A piston is positioned in the piston bore and moveable between a retracted position and an advanced position. The piston has a pressure surface exposed to fluid pressure in the actuation fluid cavity when it is away from its retracted position. A sealing member is positioned in sealing contact between the piston and the body when the piston is in its retracted position. The sealing member isolates a portion of the piston's pressure surface from the fluid pressure in the actuation fluid cavity when the piston is in its retracted position.

Fluid driven piston assembly and fuel injector using same

An injector body defines a fuel pressurization chamber, a spill passage, a stop volume and a nozzle outlet. Positioned within the injector body is a plunger which is movable between a retracted position and an advanced position. The plunger opens the spill passage to the fuel pressurization chamber over a portion of the distance between the retracted and advanced positions. The injector body also contains a needle valve member which includes a closing hydraulic surface that is exposed to fluid pressure in the stop volume. The stop volume is pressure coupled to the spill passage.

Fuel injector with controlled spill to produce split injection

A hydraulically-actuated fuel injector includes an injector body having a nozzle chamber that opens to a nozzle outlet and a plunger bore, and further has a prime spill port and an idle stability port that open to the plunger bore. A hydraulic means for pressurizing fuel in the nozzle chamber includes a plunger mounted to reciprocate in the plunger bore between a retracted position and an advanced position. A portion of the plunger bore and plunger define a fuel pressurization chamber. A needle valve member is mounted to reciprocate in the nozzle chamber between an open position in which the nozzle outlet is open and a closed position in which the nozzle outlet is closed. A portion of the plunger blocks the prime spill port when the plunger is in its retracted position. A different portion of the plunger blocks the idle stability port when the plunger is in its retracted position. The prime spill port opens to the fuel pressurization chamber over part of the plunger stroke between its retracted position and its advanced position. The idle stability port opens to the fuel pressurization chamber over a different part of the plunger stroke between its retracted position and its advanced position. The prime spill port has a relatively unrestricted flow area, whereas the idle stability port has a relatively restricted flow area about equal to that of the nozzle outlet.

Hydraulically-actuated fuel injector with idle stability port

Fuel injectors used in present day applications are normally requiring high pressure injection, short injection times and split or modified injection. Thus, this type of injection inherently produces an excess of noise. The present fuel injector assembly (22) overcomes the above deficiencies by controlling the noise emitted from a fuel injector (33). For example, as an actuation system (27) operates the fuel injector (33) the noise created by the opening and closing of the fuel injector (33) is absorbed within an isolator (34). As the fuel injector assembly (22) is installed, the fuel injector assembly (22) is positioned within a bore (26) with the fuel injector assembly being in a second position (29). And, a plurality of fasteners (28) are tightened to a predetermined value moving the fuel injector assembly (22) into a first position (24). Additionally, the fuel injector assembly (22) remains seated with respect to a cylinder (14) as the isolation material of the isolator (34) is biased positioning the fuel injector assembly (22) into the first position (24).

Fuel injector isolation

A plunger and barrel assembly includes a barrel that defines a plunger bore. A plunger having a pressure face end and a side surface is positioned in the plunger bore and moveable between an advanced position and a retracted position. An O-ring is in contact with the side surface of the plunger and the plunger bore. At least one of the plunger and the barrel define a receiver volume that opens into the plunger bore. A compressible member is positioned in the receiver volume.

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Bloomington, IL, United States of America

Ralph A Smith, Iii